Reinforced silt retention sheet

ABSTRACT

A reinforced silt retention sheet is provided for use in soil erosion control applications. The reinforced silt retention sheet includes a web of material that allows water to pass therethrough but resists the passage of silt and debris therethrough. The silt retention sheet includes one or more reinforcing elements that provide attachment points for fasteners used to fasten the sheet to support members for proper positioning during erosion control applications.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional ApplicationSerial No. 60/406,176, filed Aug. 27, 2002, which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

[0002] The present invention is directed to materials used in waterrunoff management and erosion control and, more specifically, toreinforced silt retention fabric materials.

BACKGROUND

[0003] When geotextile fabric is used in erosion control and waterrunoff management, the fabric commonly is attached with fasteners towooden or metal stakes driven into the ground to secure the fabric inposition to collect and filter dirt and debris from runoff water flows.The fasteners used typically include staples, hooks, rings or similardevices that are inserted through the fabric to attach it to the stakes.Due to its relatively thin, porous nature, however, the geotextilefabrics usually do not exhibit enough tensile strength to avoid pullingand tearing at the insertion or puncture points of the fasteners aswater, direct and debris bear against the fabric as runoff flow passestherethrough. When the fabric pulls and tears, it frequently fails tocontrol erosion effectively. Consequently, there is a need forgeotextile fabrics and sheets that resist tearing and pulling atfastener insertion points.

SUMMARY

[0004] Briefly described, the present invention generally is directed toa silt retention sheet or silt screen material having a body or web thatgenerally is formed of woven or non-woven filter material, such as aspun bond polypropylene, polyester or similar flexible polymericmaterial that allows water to pass therethrough, but substantiallyprevents silt and debris from passing therethrough. The silt retentionsheet further includes one or more reinforcing elements, strips, orbelts attached to the web at spaced intervals along or across the widthof the web. Fasteners are inserted or applied through thewater-permeable web of filter material at selected locations along thereinforcing strips to attach the web material to stakes or supportmembers.

[0005] The reinforcing elements prevent ripping and tearing of thefilter material at the points where the fasteners are inserted throughor attached to the filter material, and further provide areas forsupporting the engagement and hold of the fasteners to the filtermaterial against heavy water flows or the accumulation of sediment anddebris against the web. Some examples of the reinforcing materialinclude woven strips of nylon, reinforcing strands of fiberglass andother rugged polymeric materials. The reinforcing elements can beapplied as strands, cords, arrays, strips, patches or lengths ofmaterial attached along the web of the silt screen material bystitching, adhesion, felting, impregnation, heat fusion, weaving orsimilar means. For example, in one embodiment, the reinforced siltretention sheet includes a plurality of woven nylon strips or patchessewn onto and extending along the length of the web of filter material,with the strips spaced across the width of the web.

[0006] In another embodiment, the silt retention sheet includes a firstwater-permeable web on which is layered a second water-permeable web,with a reinforcing element disposed between portions of the first andsecond webs. The webs may be formed of woven and/or non-woven materialsand constructed so as to allow water to pass therethrough while tendingto prevent the passage of silt and/or debris therethrough. Thereinforcing element can include a plurality of reinforcing strands orstrips that form a band. A series of reinforcing bands can be formed soas to define a reinforcing structure or array extending along selectedportions of the web.

[0007] These and other aspects of the present invention are described ingreater detail below and shown in the accompanying drawings that arebriefly described as follows.

BRIEF DESCRIPTION OF DRAWINGS

[0008]FIG. 1 is a side elevational view of a portion of a silt retentionsheet encompassing principles of the present invention.

[0009]FIG. 2 is a side elevational view of a portion of the siltretention sheet of FIG. 1 fastened to support members.

[0010]FIG. 3 is a side elevational view of a portion of an additionalembodiment of a silt retention sheet encompassing principles of thepresent invention.

[0011]FIG. 4. is a side elevational view of a portion of yet anotherembodiment of a silt retention sheet encompassing principles of thepresent invention.

[0012]FIG. 5 is a side elevational view of a portion of still anotherembodiment of a silt retention sheet encompassing principles of thepresent invention.

[0013]FIG. 6 is a side elevational view of a portion of anotheralternative embodiment of a silt retention sheet encompassing principlesof the present invention.

[0014]FIG. 7 is a side view of a portion of a further alternativeembodiment of a silt retention sheet encompassing principles of thepresent invention.

DETAILED DESCRIPTION

[0015] As shown in FIGS. 1-7, wherein like numerals refer to like partsthroughout the several figures, various embodiments of reinforced siltretention sheets according to the present invention generally aredisclosed for use in soil erosion control applications. The reinforcedsilt retention sheets generally include one or more webs or sheets of asubstantially water-permeable material to which one or more reinforcingelements are attached and serve as points of attachment for fastenersthat are used to fasten the reinforced silt retention sheets to supportmembers to anchor the sheets in position to filter silt and debris fromwater passing through the sheet in soil erosion control applications.The reinforcing elements further help to reduce the incidence oftearing, pulling and separation of the water-permeable web material ator around the points of attachment for the fasteners. As used herein,the term “water-permeable” generally refers to the ability of an elementor article to allow water to pass or flow therethrough. The flow rate ofwater through a “water-permeable” structure as used in the presentinvention generally will be sufficient for soil erosion controlapplications in which storm water runoff must be filtered and allowed topass through the structure without substantial pooling or floodingaround the silt retention sheet(s) when installed.

[0016] In FIG. 1, the reinforced silt retention sheet 10 generallyincludes a sheet, blanket or web 12 formed from a geotextile fabric orother, similar water-permeable filter material to which reinforcementelements or belts 20 are attached in spaced series. The water-permeableweb of filter material 12 can be formed from woven or non-woven naturalor polymeric materials, such as spun bond polypropylene, spun bondpolyester, woven polypropylene, nylon, various woven or spun syntheticand/or natural fibers. The silt retention sheet 10 typically is of awidth of about 1-4 feet, though greater or lesser widths can be useddepending upon the application or use, and generally will be unrolled orfed out and cut to a desired length.

[0017] The reinforcement elements 20 generally are formed of a strong,resilient and substantially tear resistant material, such as woven nylonor other polymeric materials, such as spun or woven yarns, cordmaterials, fiberglass, aramid fibers or other, similar high strength,flexible materials, and are applied to the water-permeable web 12, suchas with lines of stitching 24. The reinforcement elements 20 may also beattached to the water-permeable web 12 by any other appropriate means,such as adhesives, hookand-loop fasteners, staples etc. Furthermore, thereinforcement elements 20 can be integrally formed with thewater-permeable web, such as by weaving or other non-woven fabricationprocesses by which the reinforced elements are infused or woven into thebody of the web. The reinforcement belts support and providereinforcement points at which fasteners can be attached to the web 12for securing the web to stakes or other supports. As shown in FIG. 1,the reinforced silt retention sheet 10 also includes a reinforcementborder 22 attached to the edge of the water-permeable web 12. Thereinforcement border 22 further helps to strengthen the water-permeableweb 12 and provide an additional area for attaching fasteners thereto.

[0018]FIG. 2 shows the reinforced silt retention sheet 10 of FIG. 1fastened to ground supports, such as stakes 50, by fasteners 60. Thestakes 50 typically will be wooden or metal stakes or can be formed ofany other resilient, durable materials to support the web. The fasteners60 can include staples, pins, nails, rings, clips, or any other suitablefastener for securing the web to the stakes, depending on the type ofstakes used. The fasteners 60 are fastened to the stakes 50 and insertedthrough the reinforcement elements 20 and the reinforcement border 22 toretain the sheet 10 in place. In this manner, the sheet 10 may besecurely positioned at desired locations for filtering runoff waterflowspassing through the water-permeable web 12 while preventing the passageof silt or debris therethrough. The reinforcement elements help supportthe web on the stakes 50 by providing enhanced strength at the points ofengagement of the fasteners 60 with the web to resist tearing of the webas silt and dirt build up thereagainst.

[0019]FIG. 3 shows an alternative embodiment of a reinforced siltretention sheet 110 according to the present invention. In thisembodiment, the reinforcement elements 120 generally comprise patches orstrips distributed or applied at selected locations across the sheet ofthe water-permeable material or web 112. The reinforcement elements 120may be attached to the water-permeable web 112 as discussed above withregard to attachment of the reinforcement elements 20 to web 12. Asdiscussed above, the water-permeable web 112 shown in the Figures may beany suitable material used to retain silt and debris while allowingpassage of water therethrough. The reinforcement elements 120 may bedistributed along the sheet 110 in any appropriate or desired number orpattern to provide multiple spaced areas of reinforcement and/orattachment. The web is attached via fasteners applied through thereinforcement elements to attach the web to supports such as stakes andprevent or resist tearing or pulling of the web away from the supportsas water passes therethrough.

[0020]FIG. 4 discloses another embodiment of the reinforced siltretention sheet of the present invention. In this embodiment, the siltretention sheet 210 is formed of a non-woven, water-permeable web 212composed of a suitable polymeric material. Reinforcing elements 220 areattached at spaced locations across the width of the web 212 byappropriate means, such as stitching, adhesion, felting, stapling,riveting, etc. The reinforcing elements 220 in this embodiment generallyare bands that extend longitudinally along portions of the web 212 toprovide points of attachment of fasteners to the sheet 210. The bandsmay be formed of various materials, such as woven polymeric belts,plastic strips, twisted or spun yarns, cord, ropes, spun fibers such asfiberglass, or other suitable structures. The reinforcing bands 220enable attachment of the web 212 to ground supports with various desiredspacings between the supports as needed.

[0021]FIG. 5 shows yet another embodiment of a reinforced silt retentionsheet 310. As with the silt retention sheet 210 shown in FIG. 4, thesilt retention sheet 310 generally includes a water-permeable, woven ornon-woven filtering material body or web 312 to which a series ofreinforcing elements 320 are attached. The reinforcing elements 320generally are composed of a plurality of reinforcing strips or strands322 that are aligned in proximity with each other to form bandsextending along the web 312. The reinforcing strands 322 are formed offiberglass or polymeric materials, such as polypropylene, polyester ornylon, and can be either monofilaments or yarns. As shown in FIG. 5, thereinforcing strands 322 are aligned in proximity to each other but donot intertwine or overlap. The reinforcing strands 322 can be attachedby a variety of means to the web 312, including threading or weaving thestrands through the web, felting, heat fusion or simply can be disposedwithin the web 312 during manufacture of the web. The proximity of thereinforcing strands 322 to each other to form the reinforcing elements320 tends to increase the strength of the sheet 310 in and around thereinforcing elements 320, even though the reinforcing strands do notintertwine or overlap. Nonetheless, the reinforcing strands 320 impartsufficient strength to the silt retention sheet 310 to reduce theincidents of tearing, separation and pulling of the web 312 when thesheet 310 is fastened to support members by fasteners attached to thesheet 310 at the reinforcing elements 320 as discussed above withreference to the sheet 10 of FIGS. 1 and 2.

[0022]FIG. 6 shows a further alternative silt retention sheet 410 of thepresent invention in which an array 424 of reinforcing strands 422 isprovided. As shown in FIG. 6, the reinforcing strands of the array 424intersect and overlap each other across at least a portion of the siltretention sheet 410. The array 424 further typically can include one ormore bands 421 of reinforcing materials that make up the reinforcingelements 420. The bands 421 generally are composed of two or morereinforcing strands 422 that are aligned adjacent to each other incloser proximity than the other strands within the array 424. Thereinforcing strands of the bands 421 generally are aligned parallel toeach other and may contact or overlap each other to form the bands 421.In this embodiment, the reinforcing elements 420 constitute areas alongthe sheet 410 that have higher concentrations of reinforcing strands 422than the average concentration of strands on the sheet 410. The array424 of reinforcing strands generally strengthens the web 412 to which itis attached. As shown in FIG. 6, the web 412 is composed of a non-wovenmaterial, such as spun bond polypropylene or polyester. The reinforcingstrands of the reinforcing elements 420 and the array 424 may beattached to the web 412 by various means, such as adhesion, heat fusion,impregnation, weaving, stitching, felting, etc.

[0023]FIG. 7 shows a further alternative embodiment of the reinforcedsilt retention sheet 510, which includes a first water-permeablenon-woven web 512 a on which is layered on a second water-permeablenon-woven web 512 b. An array 524 of reinforcing strands is disposedbetween the first and second webs 512 a and 512 b and includes one ormore bands 521 formed of reinforcing strands that constitute reinforcingelements 520 of the sheet 510. Although the webs 512 a and 512 b shownin FIG. 7 generally are non-woven, the present invention encompassessilt retention sheets that include woven webs that are layered on eachother to form the sheet of the present invention. For example, thereinforced silt retention sheet of the present invention may include oneor more non-woven water preamble webs layered on one or more wovenwater-permeable webs that tend to prevent the passage of silt and debristherethrough. The webs may be layered upon each other by various means,such as adhesion, interweaving, stitching, felting, heat fusion, etc. Asused herein, the term “layered on” refers to the orientation of onearticle or element relative to another and generally means that at leasta portion of one element is applied to another element in an overlappingand parallel relationship. Although FIG. 7 discloses an array 524 ofreinforced strands that form in part the reinforcing elements 520 of thesheet 510, it is to be understood that other reinforcing elements incombinations thereof shown in the various embodiments may beincorporated into a sheet in which two or more webs are layered on eachother.

[0024] It should be understood by those of skill in the art that thecertain modifications may be made to the disclosed embodiments withoutdeparting from the scope of the present invention.

What is claimed is:
 1. A silt retention sheet comprising: awater-permeable non-woven web; and, at least one reinforcing elementattached to said water-permeable non-woven web at a predeterminedlocation for receiving a fastener for attaching the silt retention sheetto a support member.
 2. The silt retention sheet of claim 1, whereinsaid water-permeable non-woven web comprises spun bond polyester.
 3. Thesilt retention sheet of claim 1, wherein said reinforcing elementcomprises a woven or non-woven band.
 4. The silt retention sheet ofclaim 3, wherein said band comprises a plurality of reinforcing strands.5. The silt retention sheet of claim 4, wherein said plurality ofreinforcing strands comprises fiberglass.
 6. The silt retention sheet ofclaim 1, further comprising a second water-permeable web layered on saidfirst water-permeable non-woven web.
 7. The silt retention sheet ofclaim 6, wherein at least one reinforcing element is disposed between aportion of said water-permeable non-woven web and a portion of saidsecond water-permeable non-woven web.
 8. A silt retention sheetcomprising: a first water-permeable web; a second water-permeable weblayered on said first water-permeable web; and, at least one reinforcingelement disposed between a portion of said first water-permeable web anda portion of said second water-permeable web.
 9. The silt retentionsheet of claim 8, wherein at least one of said first and said secondwater-permeable webs is non-woven.
 10. The silt retention sheet of claim9, wherein said non-woven web comprises spun-bond polyester.
 11. Thesilt retention sheet of claim 8, wherein said at least one reinforcingelement comprises a plurality of reinforcing bands positioned at spacedlocations along said first and second water-permeable webs.
 12. The siltretention sheet of claim 8, and wherein said at least one reinforcingelement comprises a series of strands woven or spun to form a band. 13.The silt retention sheet of claim 12, further comprising an array ofreinforcing bands applied at selected portions of said firstwater-permeable web.
 14. A silt retention sheet comprising: a firstwater-permeable non-woven web; a second water-permeable non-woven weblayered on said first water-permeable non-woven web; and, a plurality ofreinforcing elements disposed at selected locations between said firstwater-permeable non-woven web and said second water-permeable non-wovenweb.
 15. The silt retention sheet of claim 14, wherein said reinforcingelements each compose a series of woven or spun strands of a reinforcingmaterial extending along said first and said second water-permeablenon-woven webs.
 16. The silt retention element of claim 14, wherein saidplurality of reinforcing elements are aligned parallel to each other.17. The silt retention element of claim 14, wherein said first and saidsecond water-permeable non-woven webs comprise spun bond polypropylene.